Electrolytic arc-light.



No. 728,210. PATENTED MAY 19, 1903.

W. T. DEAN. ELEGTROLYTIG ARC LIGHT.

APPLICATION FILED NOV.15, 1901.

NO MODEL.

Witnesses: I Invenfiorz' WiHiamFDe'an, I

m: mums Perms co, moraurna. WASNINOTON. n, c.

Patented May 19, 1903.

UNITED STATES PATENT OFFICE.

WILLIAM T. DEAN, OF OHICAGQ ILLINOIS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTROLYTIC ARC-LIG HT.

SPECIFICATION forming part of Letters Patent N 0. 728,210, dated May 19, 1903.

Application filed November 15, 1901- Serial No. 82,346. (No model.)

To etZZ whom it may concern:

Be it known that I, WILLIAM T. DEAN, a citizen of the United States, residing at Chicago, county of Cook, State of Illinois, have invented certain new and useful Improvements in Electrolytic Arc-Lights, of which the following is a specification.

This invention relates to electric lights; and

anism' for striking an are between said elecits object is to obtain from the are formed between carbon electrodes the requisite heat to produce conductivity in a refractory substance which offers a high resistance when cold, but becomes a good conductor when heated to incandescence, this substance being included in the circuit.

The acompanying drawing is a diagram of a circuit including a lamp embodying my invention.

The mains l 2 supply current to the leads 3 4, making the circuit of the lamp, which consists of a series regulating coil A and two electrodes, each composed of a shell or tube B, of carbon, and a core 0, of some refractory oxid, such as zirconium or magnesium, which has a high resistance when cold, but is conductive when heated to incandescence. clutch mechanism D, operated by the coil A, which serves to raise the shell and strike an are between it and the lower electrode when the circuit is closed. Means are provided whereby this lifting of the upper carbon will also lift the upper core, but notuntil after the arc has been struck. A simple mode of effecting this is shown in the drawing. The upper core 0 is loose in the shells B, and at its upper end is a shoulder 0, against which the upper end of the upper shell B strikes when raised by the clutch mechanism.

The operation is as follows: When no current is flowing, the cores and shells are in contact. On closing the circuit the clutch mechanism raises the upper shell and strikes an are between it and the lower shell. At the same time the shell strikes the shoulder a and lifts the upper core. Both cores become heated in the arc until they arrive at a temperature so high that their resistance is less than that of thecarbons. The are then forms between the cores, and the increased flow of current lengthens the arc and increases the candle-power of the lamp. The

The upper shell is provided withrefractory cores remain incandescent with very little loss of material.

What I claim as'new, and desire to secure by Letters Patent of the United States, is

p 1. In an arc-lamp, the combination with an electrode, of a tubular carbon, a loose core therefor of refractory material which becomes conductive when heated, and clutch mech- 6o trode and said tubular carbon and core.

2. In an arc-lamp, the combination with an electrode, of a tubular carbon, a loose core therefor of refractory material which is of high resistance when cold but becomes conductive when heated, and clutch mechanism for separating said carbon and core successively from the other electrode.

3. In an arc-lamp, the combination with a tubular carbon, of a loose core therefor of material which is of high resistance when cold but becomes conductive when heated, a shoulder or projection on said core, and clutch mechanism for raising the carbon until it strikes said shoulderor projection and lifts said core.

4. An arc-lamp provided with a composite electrode, one portion of which is a conductor when cold and the other a conductor only when heated, the two parts being in close relation and relatively movable, and regulating mechanism for striking an are longer than the range of relative movement.

' 5. An arc-lamp electrode, comprising two conductors in close relation to one another and relatively movable, one being conductive when cold and the other only when heated,and a stop in fixed relation to one of said conductors to limit the range of relative movement. 0

6. In an arc-lamp, the combination with a regulating magnet and clutch, of a composite electrode, one part of which is a conductor when cold and the other only when heated, the two being in close relation and movable 5 relatively to one another and to the cooperating electrode of the lamp, and means for limiting the extent of relative movement.

In witness whereof I have hereunto set my hand this 11th day of November, 1901.

' WVILLIAM T. DEAN. Witnesses:

FRANK DEAN, WILLIAM GRAY. 

